Wake up from sleeping mode doesn't work

Projects Programming
6

Good point! I just set count to "0" in my condition "if". It works well, when I attach smartphone to NFC tag, Arduino is triggered - sensor messures and led is lighted up.

But another problem occured. When I leave smartphone on the tag for longer time (Pin 2 stays LOW even after condition is met - Arduino is triggered) and then I take it from the NFC tag and return it back. Arduino is not triggered again. I don't know why shouldn't be triggered.

My code is following:

#include <Wire.h>
#include <avr/interrupt.h>
#include <avr/sleep.h>
#include "SparkFunISL29125.h"

int ledPin = 13;            // LED connected to digital pin 13
int count = 0;


void wakeUpNow()        // here the interrupt is handled after wakeup
{
  sleep_disable();
  detachInterrupt (0);
}



SFE_ISL29125 RGB_sensor;

void setup()
{

  pinMode(ledPin, OUTPUT);         // sets the digital pin as output
  pinMode(2,INPUT_PULLUP);
 
  Serial.begin(9600);
  Wire.begin();

 // Inicialization of sensor
  if (RGB_sensor.init())
  {
    Serial.println("Sensor Initialization Successful\n\r");
  }

}

void sleepNow()
{
  set_sleep_mode (SLEEP_MODE_PWR_DOWN);   
  sleep_enable ();          // enables the sleep bit in the mcucr register
  attachInterrupt (0,wakeUpNow, LOW);  // wake up on low level on D2
  sleep_mode ();            // here the device is actually put to sleep!!
}  // end of sleepNow



void loop()
{
// Light up led diode and read from RGB sensor
  detachInterrupt (0); 
  digitalWrite(ledPin, HIGH);
  delay (500);
  unsigned int red = RGB_sensor.readRed();

  Serial.print("Red: "); Serial.println(red, DEC);
  Serial.println();
  
// Write to NFC tag EEPROM memory
  Wire.beginTransmission(25); 
  Wire.write(0x40); 
  Wire.write(0x55); 
  Wire.write(0x00); 
  Wire.write(red);  
  Wire.write(red>>8); 
  Wire.write(0x00);
  Wire.write(0x00); 
  Wire.endTransmission();     

  count++;

  delay(2000); 
  
  if (count==2){
  digitalWrite(ledPin, LOW);
  digitalWrite(2, HIGH);
  count = 0;
  delay(100);
  sleepNow();
  }
}